stdio/asprintf.c

   1 /*      $OpenBSD: asprintf.c,v 1.4 1998/06/21 22:13:46 millert Exp $    */
   2
   3 /*
   4  * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. The name of the author may not be used to endorse or promote products
  16  *    derived from this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  19  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  20  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  21  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  22  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  23  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  24  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  25  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  26  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  27  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #if defined(LIBC_RCS) && !defined(lint)
  31 static char rcsid[] = "$FreeBSD: src/lib/libc/stdio/asprintf.c,v 1.6 1999/08/28 00:00:55 peter Exp $";
  32 #endif /* LIBC_RCS and not lint */
  33
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <errno.h>
  37 #if __STDC__
  38 #include <stdarg.h>
  39 #else
  40 #include <varargs.h>
  41 #endif
  42
  43 int
  44 #if __STDC__
  45 asprintf(char **str, char const *fmt, ...)
  46 #else
  47 asprintf(str, fmt, va_alist)
  48         char **str;
  49         const char *fmt;
  50         va_dcl
  51 #endif
  52 {
  53         int ret;
  54         va_list ap;
  55         FILE f;
  56
  57 #if __STDC__
  58         va_start(ap, fmt);
  59 #else
  60         va_start(ap);
  61 #endif
  62         f._file = -1;
  63         f._flags = __SWR | __SSTR | __SALC;
  64         f._bf._base = f._p = (unsigned char *)malloc(128);
  65         if (f._bf._base == NULL) {
  66                 *str = NULL;
  67                 errno = ENOMEM;
  68                 return (-1);
  69         }
  70         f._bf._size = f._w = 127;               /* Leave room for the NULL */
  71         ret = vfprintf(&f, fmt, ap);
  72         *f._p = '\0';
  73         va_end(ap);
  74         f._bf._base = reallocf(f._bf._base, f._bf._size + 1);
  75         if (f._bf._base == NULL) {
  76                 errno = ENOMEM;
  77                 ret = -1;
  78         }
  79         *str = (char *)f._bf._base;
  80         return (ret);
  81 }